<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta id='viewport' name="viewport" content="initial-scale=1.0" />
    <title>metaViewport</title>
</head>
<body>
    <span>hello world!</span>
</body>
</html>
<script type="text/javascript">
 function isElementMetaViewport () {
    let beforeWindowInnerWidth = window.innerWidth

     console.log('beforeWindowInnerWidth'+beforeWindowInnerWidth)
      var viewport = document.getElementById("viewport");
    viewport.content = "initial-scale=2.0"
    let afterWindowInnerWidth = window.innerWidth
    console.log('afterWindowInnerWidth'+afterWindowInnerWidth)
    return beforeWindowInnerWidth !== afterWindowInnerWidth
  }
</script>
<style>
</style>
